Apparatus for offset printing capsules

ABSTRACT

Apparatus for printing cylindrical hard shell capsule parts formed on the row of pins of a capsule mold pin bar. The apparatus includes a platen with a row of deformable printing pads spaced so that the respective pads and capsule parts are in registry when the two rows are brought together in printing relation.

United States Patent 1 1 1 1 3,910,183 Noren et al. 1 Oct. 7, 1975 54] APPARATUS FOR OFFSET PRINTING 1,997,652 4/1935 Pesci 101/16 3 X CAPSULES 2,636,215 4/1953 Smith 425/270 x 2,748,696 6/l956 Murray l0l/4l [75] Inventors: Oscar B. Noren, Grosse Pomte 2,342,046 7/1958 Murray 101/41 Farms; Stephen Balog, Farmington 3,090,305 5/196 3 Keck t 101/334 Hills; Carl C. Garland, Detroit, all 3,688,695 9/1972 James 101/44 X f Mich 3,763,774 10 1973 Pearl et a1 101/301 x 3,794,453 2/1974 Padilla et al. 425/269 X [73]- Ass1gnee: Parke, Davis & Company, Detroit,

' Mich.

[ 1 Filed: Feb. 1974 Przmary Exammer-Chfford D. Crowder [21] Appl. No.: 446,894

[57] ABSTRACT [52] U.S. Cl. 101/41; 10l/163; lOl/301;

2 4/132; 425/304 Apparatus for printing cylindrical hard shell capsule [51] Int. Cl. B41F 17/36 Parts formed the row of P Of a Capsula mold P 58] Field of Search 425/804, 93, 269, 270; The apparatus includes a platen with a row of 264/132, 294, 301; 101/301, 150, 163, 41, formable printing pads spaced so that the respective 44 333 334 42 pads and capsule parts are in registry when the two rows are brought together in printing relation. [56] References Cited UNITED STATES PATENTS 3 Claims, 8 Drawing Figures 1,787,777 1/1931 Colton 425/804 X U.S. Patent 0a. 7,1975 Sheet 1 of2 3,910,183

XXXXXXXXXXXXXXXX Sheet 2 of 2 3,9l0,183

U.S. Patent Oct. 7,1975

APPARATUS FOR OFFSET PRINTING CAPSULES SUMMARY AND DETAILED DESCRIPTION This invention relates to means for printing cylindrical hard shell capsule parts formed on a capsule mold pin bar. More particularly, this invention relates to apparatus for printing pin-mounted capsule parts and to a method which includes printing capsule parts while mounted on the mold pin bar.

Prior to the invention, printed cylindrical hard shell capsules were produced by telescopically joining the empty capsule parts (i.e., the capsule cap and the capsule body) and then printing each joined capsule on its cylindrical side wall, usually by passing the capsule in timed relation against the circumference of a moving offset printing roll. The prior art printing methods have been generally satisfactory but have been somewhat limited in regard to choice of location of the printed legend on the capsule surface. The prior methods have also been time-consuming and have required operations subsequent to the capsule production operation. Despite the need for greater efficiency, the mentioned conventional printing has nevertheless continued in use for lack of better procedures.

It is therefore an object of the present invention to provide efficient, economical means for printing hard shell cylindrical capsules.

It is also an object of the invention to provide a method for printing a cylindrical hard shell capsule part on any of its surfaces such as its cylindrical side wall or its closed end or domed end.

It is a further object of the invention to provide economical means for printing hard shell capsule parts an an intermediate step in their manufacture on a hard capsule manufacturing machine prior to the step of stripping the capsule parts from the capsule mold pins.

These and other objects, purposes and advantages of the present invention will be seen from the following specification and the accompanying drawing in which:

FIG. 1 is a side elevational view, partly cut away, of a printing machine according to the invention;

FIG. 2 is a top view of the machine;

FIG. 3 is a fragmented front view of a capsule pin bar and cooperating printing pads or heads;

FIG. 4 is an end view of a capsule pin bar in a mounting fixture (partly sectioned) at the printing station;

FIG. 5 is a fragmented view taken on lines 55 of FIG. 4;

FIG. 6a is a view in elevation of a capsule pin supporting a capsule part;

FIG. 6b is a top view of the pin and capsule part; and

FIG. 7 is a view in elevation of a capsule pin supporting a capsule part.

The apparatus, according to the present invention for printing capsule parts, comprises a capsule mold pin bar carrying perpendicularly a row of evenly spaced capsule mold pins adapted for forming capsule parts by the dip molding technique, means for transferring the pin bar to and from a printing station, platen means carrying a row of evenly spaced deformable pads each having a printing surface, the said pin row and printing surface row being mutually matched such that the respective pins and printing surfaces are in registry when the two rows are brought together in printing relation, means for inking said printing surfaces, and means for bringing said rows into registry at the printing station such that a predetermined portion of the capsule part formed on each pin can be printed.

The invention also contemplates the method of printing capsule parts comprising dipping bar-mounted capsule pins in capsule dipping solution to provide a film coating of liquid dipping solution on each pin, drying the coating on the pins to provide pin-mounted capsule parts, printing the capsule parts while mounted on the pins and stripping the printed capsule parts from the pins. In this method, the steps of clipping, drying and stripping can be carried out in any suitable way, for example, by use of a machine of the type described in Colton US. Pat. No. 1,787,777.

Referring to the apparatus in detail of which FIGS. 1, 2 and 3 illustrate a preferred embodiment, there is shown a capsule mold pin bar 10, carrying a row of spaced capsule mold pins 11, positioned at a printing station 30 of a capsule printer 20. The printer has a rectilinear housing 21 which in turn is adjustably mounted (at three points) on a base 22 by means of a cross member 21a carried pivotally by a pair of spaced arms 22a and by an adjusting screw 22b threadably received in the base 22. A printing platen 23 having a handle 23a is pivotally mounted by a parallelogram linkage on the housing 21 for reciprocation, i.e., by four arms 24 attached by platen pivots 25a! and housing pivots 25b. The underside of the platen carries a set of resilient printing pads 26 rigidly secured by pad sockets 27. The printing pads correspond in number and in placement beneath the platen to the number of pins 11 of the pin bar 10 so that the tips 28 of the pads and the domed end 18 of the capsule part 14 can be brought together in matching coaxial engagement. As seen in FIG. 1, an area on the front of the capsule printer 20 constitutes a printing station 30 which includes a pin bar fixture 31 for mounting a capsule mold. pin bar 10. In a modified embodiment used forprinting the cylindrical side 16 of the capsule part 14 (as shown in FIGS. 4 and 5), the top of the fixture 31 is provided with a mounting slot 32a of a size just sufficient to accommodate the entry of a pin bar to a depth such that the side of each pin 11 can be brought into aligning contact with the top of the fixture in a channel 33a. As seen in FIG. 3, the pin bar fixture 31 has the same length as the pin bar and supports a keeper 32 at its ends. These, having an overhanging extension 32b, fit closely on the ends of the pin bar, serving to locate the vertical and longitudinal placement of the pin bar into the fixture 31. The fixture in turn is removably attached to the base 22 so that the mount can be interchanged with any of various pin bar fixtures having different configurations for end printing or side printing or being adapted to accommodate pin bars of different standard sizes.

At what may be regarded as the rear of the capsule printer 20 is an inking station 40. The inking station has an inkwell 41 removably mounted upon the housing 21 for servicing. A gravure roll 42 is joumaled for rotation part-way within the well to pick up liquid ink contained in the well. The gravure roll has on its circumference an axial row of gravure recesses 43. The gravure recesses correspond in number and in spacing to the printing pads 26 such that the pads can be brought intoone-toone contact with the gravure recesses. The gravure roll is adapted to be indexed one turn at a time by clockwise rotation by means of indexing wheel 46 carried on a shaft 45 and is provided with a doctor blade 44.

OPERATION The invention contemplates operation of the described printing apparatus with a hard shell capsule production machine in which the capsules are produced using the clipping technique. One such machine is the type described in Colton US. Pat. No. 1,787,777. In the production of capsules using this technique a row of capsule mold pins carried on a bar, as indicated, are dipped into capsule dipping solution (usually aqueous gelatin), the pin bar carrying the film-coated pins is elevated and the film dried. The dried capsule parts thus produced are stripped from the pins, cut (at line and joined telescopically with matching capsule parts. The stripped pins are then greased, dipped again and the operation cycle of steps is repeated indefinitely. The present invention contemplates printing barmounted capsule parts and further contemplates printing the capsule parts at a stage in the operation when they are sufficiently dry, usually just prior to stripping from the pins. At this stage and, in any event, prior to reaching the stripping operation, each pin bar carrying the dried capsule parts is transferred to the printing station 30 (manually or by automated means) and mounted on the pin bar fixture 31. For end printing, mounting is accomplished by sliding the ends of the bar between the keepers 32 and below the keeper extensions 32b to backstop 33. The latter serves to fix the lateral position of the pin bar whereas the keepers 32 fix the lengthwise position. The fixture 31 and the keeper extensions 32b retain the bar. For side printing, the pin bar is mounted simply by laying the bar into the slot 320 and pin channels 33a (FIGS. 4 and 5). The printer is operated by raising the platen 23 held in the position shown in broken outline at the inking station and reciprocating the platen to the printing position shown in solid outline in the printing station 30. At this inking position each of the printing pads 26 receives an ink impression (the ink being a quick-drying ink of phar maceutical grade) from the gravure roll recess 43. When the platen is reciprocated to the printing position, the pad tips 28 thereby each carry the fresh impression precisely on center to the end of the capsule mold pin, being deformed during the printing stroke such that the printmark 19a (FIGS. 6a and 6b) registers symmetrically over the predetermined portion of the curvature of the domed end 18 of the capsule part. The undistorted profile of the printing pad 26 in this regard is seen in FIG. 3 whereas the deformed profile of the pad under compression of the pin end is seen in FIG. 1. Advantageously, the printing action can serve to cover a limited area or a more extensive curvilinear portion of the capsule part, as desired, whether as a side print 19b on the side wall 16 or an end print 19a on the domed convex end 18, as shown in FIGS. 6a, 6b and 7.

As indicated above, the pin bar fixture 31 can take any of several forms to achieve different purposes, the fixture illustrated in FIG. 1 being used for printing the ends of capsule parts and the fixture illustrated in FIGS. 4 and 5 being used for printing the cylindrical capsule wall of the capsule part.

- The apparatus, as indicated, can be used with different standard size pin bars and different pin bar fixtures and also in adjustable to accommodate differences in dimension from one pin size to another. For this purpose, the front portion of the'housing 21 can be raised or lowered by means of the adjusting screw 22b to any desired position of adjustment so that the printing contact and printing pressure will be correct for every occasion. The pin pressure can be varied as required to achieve coverage over the predetermined portion of the capsule part being printed. For example, using a 30- pin bar the printing force typically can measure about 5 pounds per pin to achieve an end print 19a having a latitude extending approximately to the capsule part shoulder 17 as illustrated in FIGS. 6a and 6b.

The printing action takes place on all of the pins of the pin bar simultaneously and is accomplished in a short period of time, for example, of the order of onequarter of a second, whereupon the operation is continued by raising the platen from the printing position and returning it in reciprocal fashion to the inking position shown in broken outline Prior to return of the platen to this position, the operator indexes the gravure roll one turn so that the row of inked gravure recesses 43 by this action is brought from the body of ink in the inkwell 41 past the doctor blade 44 to a point uppermost on the roll filled with a measured quantity of fresh printing ink. Thus, when the platen is lowered to the end position each of the printing pads 26 carried on the underside of the platen are brought into engagement with the gravure roll and deformed under the pressure of the stroke so that the ink carried in each of the gravure recesses 43 is well contacted by the surface of the pad tips 28. When the platen again is moved back to the printing position for the next cycle the withdrawal of the pad from the surface of the gravure roll serves to deplete each gravure recess 43 of ink thus leaving the same dry. In this way potential problems with dry ink residues in the gravure recesses are avoided. The cycle is completed by withdrawing the pin bar from the fixture 31 and returning the pin bar and its printed capsule parts to its place, left temporarily vacant, in the capsule production machine for stripping, cutting, joining, etc. in the usual manner. The printer is now ready for the next cycle of pin bar transfer, printing, inking and pin bar removal.

For purposes of the invention, conventional fastdrying inks used for printing capsules are satisfactory. For best results soft elastomer and particularly silicone nlbber is used for the printing pad, preferably a low durometer silicone such as a 5-25 durometer silicone. For use with a conventional 30-pin bar a convenient pad diameter is approximately five-eighths inch. Pads suitable for purposes of the invention are commercially available. The invention is applicable to any of various sizes of capsule parts, both body parts and cap parts, ranging, for example, from small (No. 5) to large (O00) capsule parts. Moreover, the invention contemplates the use of any of a wide range of ink colors, designs, configurations and lettering types, as desired.

While the invention in apparatus and method for printing has been described in considerable detail, it will be realized that wide variation in such detail can be made by those skilled in the art without departing from the spirit of the invention as hereinafter claimed.

We claim:

1. Apparatus for printing capsule parts comprising a capsule mold pin bar carrying perpendicularly a row of capsule mold pins adapted for forming capsule parts by the dip molding technique,

fixture means for mounting the pin bar at a printing station,

platen means carrying a row of deformable offset printing pad surfaces, the said pin row and printing surface row being mutually matched such that all of the respective pins and printing surfaces are in registry when the two rows are brought together in printing relation, the platen means being mounted by a parallelogram linkage to reciprocate between an inking position and a printing position,

gravure means for inking said printing surfaces comprising an offset gravure roll carrying peripheral gravure recesses corresponding in number and in spacing to the printing pad surfaces such that said surfaces can be brought into one-to-one contact with the gravure recesses in the inking position, and means for bringing said rows into registry at the printing station such that a predetermined portion of a 5 capsule part formed on each pin can be printed.

2. Apparatus according to claim 1 where the printing pads are formed of soft silicone rubber.

3. Apparatus according to claim 1 wherein the capsule mold pin bar carries a row of 30 pins and is 10 adapted for forming capsule parts by the dip molding technique in a hard shell capsule manufacturing ma chine. 

1. Apparatus for printing capsule parts comprising a capsule mold pin bar carrying perpendicularly a row of capsule mold pins adapted for forming capsule parts by the dip molding technique, fixture means for mounting the pin bar at a printing station, platen means carrying a row of deformable offset printing pad surfaces, the said pin row and printing surface row being mutually matched such that all of the respective pins and printing surfaces are in registry when the two rows are brought together in printing relation, the platen means being mounted by a parallelogram linkage to reciprocate between an inking position and a printing position, gravure means for inking said printing surfaces comprising an offset gravure roll carrying peripheral gravure recesses corresponding in number and in spacing to the printing pad surfaces such that said surfaces can be brought into one-to-one contact with the gravure recesses in the inking position, and means for bringing said rows into registry at the printing station such that a predetermined portion of a capsule part forMed on each pin can be printed.
 2. Apparatus according to claim 1 where the printing pads are formed of soft silicone rubber.
 3. Apparatus according to claim 1 wherein the capsule mold pin bar carries a row of 30 pins and is adapted for forming capsule parts by the dip molding technique in a hard shell capsule manufacturing machine. 